Railway brake-controlling apparatus



Sept. 16, 1930. L. BUCK 5 1,775,809

RAILWAY BRAKE CONTROLLING APPARATUS Filed Feb. 21, 1930 Note: P4004 c'onneczed iopg'pefl with Enginevmfs Brake lzlVe 22 Release, Running: Holding orlap pas z'zions, andblarzked Wz'zlz flrake Valve in Serra-e or R Emolyelzcyposz'ziozzs.

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Q-R-1/ Wa UNITED ST E Patented Sept. 16, 1930 LEb U K 9 PITTSBURGH,"PENIiTSYLVANIA, ASSIGNOR-TQ'THE 11mm sWI'fcH' a SIGNAL, COMPANY, or sWIssvALE; PENNSYLVANIA, A conronmion OF E RAILWAY BRAKESQNTROLLING APPARATUS f Application filediFebruaryi21,1330. Serial No. 430,192,

- My invention relates to railway brake controlling apparatus, and particularly to "ap paratusof the typeinvolving means for causing an automatic brake application when a 'train enters a caution block, together with means for restraining or preventing such automatic application if the engineman operateshis'brake valve in suchmanner as to cause a manual application of the'brakes.

Heretofore the customary practice has been tomakethe automatic brake application a service application, but on some railroads the block lengthsa're such that a service appl cation must 'occur'immediately upon entering the block in order to reduce a train from full speedto stop at theend of the block. In suchinstances it is impractical to use service application for an automatic apphcat on ofthe'bralee s' because a certain delay period is necessary within which the engineer may apply the brakes manually, thereby preventing the automatic applicationgand s'uchdelay erio'd plus service braking distance w1ll exceed the block length; One feature ofmy 1nvention is the provision of means operating to cause a'n' emergency brake application after thelapse of: a fixed time'interval following the entrance of a train into-acaution block,

thefiXed time interval plus maximum emergency' braking distance being substantially equal to the block length. J I willdesc-ribe one form of apparatus embodying my inventionygand will then point out thegnovelfeatures thereofi in claims.

" the accompanying drawing; Fig. 1 is a of ap-v paratus embodying my lnventlon'. Flg. 2"

diagrammatic view showing one form is a view showin'gby'means ofcurv'es'one man; ner of utilizing the apparatus illustrated 1n fieferring first to Fig. 2, the reference character T 'designateS- aFraiIWay track along which trafiic normally'moves in the direction indicatedby the; arrow, which track is dividediby insulated oints 8 to form a lurality of blocks, of which-only one block perhour, and ifiaiservice application occurs ''H is shown'in the drawing; These blocks are of at the moment thet'i'ain enters the block, the;

train will bebrought'to a full stop just-before reaching the; exit end of the block. This is illustrated in Fig. 2 by the curve Y, it being assumed that a manualservice application of the brakesoccurs at the point Y Under these conditions the train will be brought to a stop at pointlYi which isabout 200 ft. in the rear of the exit end of the block. The effect of an emergency application of the brakes is represented by the curve X. Ifthis applicaa tion occurs at the point X which is about 7 50 it. from the entrance end of theblock, and it the train is traveling at miles per hour when the application occurs, the train will be brought to a'stop at substantially point Y that is, at substantially the same point as before; A'train traveling at 60 miles per hour will consume approximately 9 seconds 111 covleaving the block. g Referring now to Fig. 1, the reference character R designates a relay which is controlled from the trackway in such manner that the relay is energized under'safe trafiicbondi tions, but becomes deenergized when the train enters a caution block. The apparatus for controlling this relay, forms no part of my present invention, and, consequently, it is omittedfrom the drawing. A

magnet K is controlled by front contacts 6 and 7 of relay R, with the'result that this magnet is energized or deenergized accord ing as the relay is energized or deenergi'zed. Magnet K controls a valve F, which valve in turn controls the supply of fluidpressure to two reservoirsA and B. Whenthe valve F is ingthe position shown-,' that is,- when .mag'net K is'energized, reservoir A is connected with a source of fluid pressure through pipes9 and 2 and reservoir B is disconnected fromboth reservoir A and the source of pressure. VVhen magnet K becomes deenergized valve Fwill reverse; thereby disconnecting reservoir A from the source of pressure andconnecting this'reservoir with reservoir 13 through a g '1 restricted orifice (land a pipe The condition which will then exist is determined by the position of the engineers brake valve M. If this valve is in the release, running, holding or lap position, reservoir B will be connected with atmosphere through a pipe 4, a port in the engineers brake valve M, a pipe 5 and a whistle 7. Under this condition, the pressure in reservoir A will gradually reduce to atmospheric value through the restricted orifice C. If, on the other hand, the engineers brake valve M is in the service or the emergency position, pipe 4 will be blanked, and under this condition the air in reservoir A will gradually be reduced to an intermediate value determined by the equalization pressure of reservoirs A and B.

The reference character D designates a pressure responsive (,evice which is connected with reservoir A through a pipe 1, and which in turn controls a valve The pressure responsive device 1) comprises a cylinder containing a piston 11 which is biased upwardly 3y a spring 12. Vhcn the pressure in reservoir A is above the intermediate value referred to hereinbefo-re, this pressure overbalances the effect of spring 12 and the piston 11 occupies the position in which it is shown in the drawing. When the pressure in reservoir A drops below this intermediate value, piston 11 will rise and will therefore reverse the position of the valve member 13 in valve E. hen valve member 13 occupies the position in which it is shown in the drawing, the brake pipe is closed, but when this valve member rises, the brake pipe becomes directly connected'with atmosphere through. an exhaust port 14 and this will result in an emergency application of the brakes.

Assuming that reservoir B is connected with atmosphere when magnet K becomes deenergized, the parts are so proportioned and adjusted that a period of about 9 seconds will elapse before valve E will reverse to cause the emergency application of the brakes.

Reverting now to Fig. 2, I will assume that a. train equipped with the appa ratus shown in Fig. 1 passes caution signal S at miles per hour. If the enginema-n moves his brake valve to the service position at point Y that is, immediately upon passing signal {5 the train will be brought to a stop at point- Y and the operation of the emergency brake valve E will be prevented. If, however, the engineer takes no action in response to the caution indication given by signal S brake valve E will reverse at approximately X with the result that the train will be brought to a stop at the same point, namely, point Y Although I have herein shown and de scribed only one form of apparatus embodying my invention, it is understood that various changes and modifications may be made therein within the scope of the appended claims without departing from the spirit and scope of my invention.

Having thus described my invention, what I claim is:

1. Train-carried apparatus for an automatic train control system, comprising a magnet controlled from the trackway in such manner as to be energized under safe trafiic conditions and to become deenergized when the train enters a caution block, two reservoirs A and B, a source of fluid pressure; a valve device so controlled by said magnet that when the magnet is energized reservoir A is connected with said source of fluid pressure but reservoir B is disconnected from the source and from reservoir A, whereas when the magnet becomes deenergized reservoir A is disconnected from said source and is connected. with reservoir B through av restricted orifice; a port associated with the usual enginecrs brake valve for connecting reservoir B with atmosphere at all times except when such valve is in the service or emergency position; whereby when said magnet becomes deenergized the pressure in reservoir A will gradually drop to an intermediate pressure or to atmospheric pressure according as the engineers valve is or is not in a brake-applying position, and a valve responsive to the pressure in reservoir A and operating to cause an emergency application of the brakes when the pressure in reservoir A drops below said intermediate value.

2. Railway traflic controlling apparatus comprising a track divided into blocks of such lengths that substantially an entire block is required to reduce a train from full speed to a stop by a service brake application, a train-carried magnet so controlled from the trackway as to be energized under safe trailic conditions and to become deenergized when the train enters a caution block, two reservoirs A and B, a source of fluid pressure; a valve device so controlled by said magnet that when the magnet is energized reservoir A is connected with said source of fluid pressure but reservoir B is disconnected from the source and from reservoir A, whereas when the magnet becomes deenergized reservoir A is disconnected from said source and is connected with reservoir B through a restricted orifice; a port associated with the usual engineers brake valve for connecting reservoir B with atmosphere at all times except when such valve is in the service or emergency position; whereby when said magnet becomes deenergized the pressure in reservoir A will gradually drop to an intermediate pressure or to atmospheric pressure according as the engineefis valve is or is not in a brake-applying position, and a valve responsive to the pressure in reservoir A and operating to cause an emergency application of the brakes when the pressure in reservoir A drops below said intermediate value, the time interval required for the pressure in reservoir A to drop below said intermediate Value being such that the resulting emergency brake application will reduce the train from full speed to a stop at substantially the end of the caution block.

In testimony whereof I affix my signature.

LEO L. BUCK. 

